A semiconductor device manufacturing method is known in the related art, which includes: loading a plurality of substrates arranged in a direction perpendicular to substrate processing surfaces into a process chamber installed within a reaction tube whose outer periphery is surrounded by a heating device; and processing the substrates by introducing a gas into a gas introduction pipe, which is installed on a side surface of a substrate processing region inside the reaction tube to reach at least an outer side of the heating device, and then discharging the gas into the process chamber from discharging ports having a slit shape with a size corresponding to at least two or more substrates and arranged in the direction perpendicular to the substrate processing surfaces.
In the above-mentioned semiconductor device manufacturing method, a substrate processing process intends to enhance an in-plane uniformity and an inter-plane uniformity of the plurality of substrates by forming a side flow for each of multiple gas introduction partition parts and equalizing the amount of gas entering between the substrates by introducing the gas into the multiple gas introduction partition parts, which are installed in the gas introduction pipe and separated from one another by partition walls in the direction perpendicular to the substrate processing surfaces, and then discharging the gas into the process chamber from a discharging port installed in each of the multiple gas introduction partition parts.
However, even though the gas introduction partition parts are separated from one another by the partition walls in the above-described configuration of the semiconductor device manufacturing method, there are clearances which are not separated from one another between the partition walls and the substrates in the vertical direction, and the gas may move up and down through the clearances. Due to this, it may be difficult to form side flows having a uniform amount of gas in the gas introduction partition parts.
Further, particles are likely to be generated in upper and lower parts in the process chamber, and the particles can freely move up and down through the above-described clearances. Due to this, it is difficult to effectively restrict the particles from being spread over the substrates.